Ebola

Ebola

COLD STORAGE An Ebola vaccine tested in West Africa is stored at –80° C in a canister that researchers can take out into the field. More than 5,000 people in Guinea received the vaccine in a trial to gauge its efficacy.

Of 5,837 people in Guinea and Sierra Leone who received a single shot of the vaccine, rVSV-ZEBOV, none became infected with the virus 10 to 84 days after vaccination. That’s 100 percent protection, researchers report online December 22 in the Lancet.

World Health Organization researcher Ana Maria Henao-Restrepo and colleagues tested a “ring vaccination” approach, immediately vaccinating family members and other contacts of people infected with Ebola. This strategy seemed to staunch the virus’ spread. Among 4,507 people never vaccinated or who got a delayed vaccine, 23 contracted Ebola.

The findings echo preliminary results (SN: 9/5/15, p. 6) and offer a promising line of defense for future outbreaks. But scientists do not know how long the vaccine’s protection lasts.